St. Louis, the reigning National Hockey League scoring champion and former most valuable player, had been controversially left out of Canada's original roster announced last month despite sitting near the top of the scoring race.
Hockey Canada said in a statement that Stamkos, twice winner of the Rocket Richard trophy as the NHL's goal-scoring champion, had not been cleared to take part in the Olympic tournament that starts on Feb. 12 after a scan revealed his fractured right tibia had not healed sufficiently.
Stamkos, who turns 24 on Friday, sustained the injury during a game against the Boston Bruins in November, causing him to miss 39 regular-season games.
The twice NHL All-Star was tied with Alex Steen as the NHL's top goal scorer, and with Sidney Crosby for the points lead at the time of his injury.
The 38-year-old St. Louis leads the Lightning in scoring this season with 25 goals and 54 points in 56 games.
Canada begin the defence of their Olympic gold medal on Feb. 13 against Norway.